The present invention relates generally to an apparatus and method for preparing a leading edge of a roll of web material. In particular, the present invention is an apparatus and method for tensioning web material of a roll of web material for the formation of a cut leading edge and the subsequent application of flying splice adhesive tape to the cut leading edge of the roll of web material.
In the newspaper and magazine publishing industry, the lengths of web material (i.e., paper), from which individual newspapers or magazines are printed, are contained on rolls (i.e., elongate members). Typically, the length of web material or a roll is fixed, and the web material is continuous from its trailing edge at the core or the roll to its leading edge at the periphery or the roll. The length or web material from an individual roll is fed into a printing apparatus where print and/of pictures are applied to the web material in a continuous automated process. Next, the length of web material is cut into sheets of desired size and then these sheets are assembled into individual newspapers of magazines. The cutting of the sheets and the assembling of the sheets into their final print medium format is once again, a continuous, automated process. Typically, during the continuous process of printing, cutting and assembling or the print medium, the length of web material travels at speeds of between 2000 and 3000 feet per minute. Hence, large numbers of individual newspapers or magazines can be produced in a relatively short period of time.
A disadvantage in the use of the rolls of web material occurs when splicing a leading edge of a "new" roll of web material to the trailing edge of an "old" roll of web material currently traveling through the continuous printing, cutting and assembling process. This type of new-to-old roll connection is referred to as a "flying splice", and is a splice made between an expiring or leading roll of web material and a new of following roll of web material in a continuous manner without reducing either the equipment speed or the speed of the web. Typically, to splice the leading edge of the new roll to the trailing edge of the old roll, the web material of the roll of web material is first manually trimmed to form a cut leading edge of web material. Subsequent to the formation of the cut leading edge, one or more pieces of adhesive tape are manually applied to the cut leading edge of the new roll of web material. Adhesive, such as pressure sensitive adhesive, on a bottom surface of the tape secures the tape to the leading edge. With the tape secured to the leading edge of the new roll the leading edge of the new roll is brought into contact with the old roll, where adhesive, such as pressure sensitive adhesive, on the top surface of the tape secures the leading edge of the new roll of web material to the trailing edge of the old roll of web material. Once the splicing process is complete, movement of the web material of the old roll, through the apparatus performing the printing, cutting and assembling process, acts to continuously and automatically thread the web material of the new roll into the printing, cutting and assembling apparatus. Due to the complex and mostly manual nature of timing the cut leading edge of web material and for applying flying splice adhesive tape to the cut leading edge of a roll of web material, the process is tedious, cumbersome and time consuming. Operator time to manually prepare the cut leading edge and apply a flying splice preparation pattern to the cut leading edge of web material may range from about 4-8 minutes for small rolls and/or 5-15 minutes for large rolls depending on press speed and operator efficiency.
In addition, the hand work required by one or more people to manually from the cut leading edge and apply a piece or pieces of flying splice adhesive tape to the cut leading edge of web material is not condusive to the accurate formation of the cut leading edge or the accurate positioning of the tape on the cut leading edge of the web material. In particular, the use of manual techniques to form the cut leading edge may result in a cut leading edge of undesired or misformed shape (e.g., a waveform leading edge when a straight leading edge is desired) which may affect subsequent positioning of the adhesive tape and tape separation during the "flying splice" process. Moreover, adhesive (particularly pressure sensitive adhesive) on the top and bottom surfaces of the flying splice adhesive tape tends to adhere to the leading edge of the web material virtually on contact, making repositioning of the tape difficult, and thereby further complicating the process of accurately aligning the tape on the leading edge of the web material. In accurate formation of the cut leading edge and subsequent misalignment of the flying splice adhesive tape on the cut leading edge of the web material may result in the leading edge of the new roll being incorrectly applied to the trailing edge of the old roll, which may cause the new web of material to be improperly threaded into the apparatus performing the printing, cutting and assembling process. Incorrect feeding of the new web material into the apparatus may cause the apparatus to seize resulting in machine down time and lost production time.
Apparatus for forming a cut leading edge and for applying flying splice adhesive tape to the cut leading edge of a roll of web material are generally known. Canadian patent application 2,069,247 to Norbert et al. discloses one such apparatus for preparing a leading edge of a new roll of web material for a flying splice. The apparatus of Norbert et al. includes a base plate for carrying a knife support block that extends substantially parallel to the axis of rotation of the roll of web material. A cutting knife of the cutting block forms the cut leading edge of the roll of web material while a perforating blade forms a perforated region in the web material spaced from the leading edge. The cutting knife and perforating blade are parallel to one another and to the axis of rotation of the web material roll. The base plate further carries an adhesive application block for holding adhesive. The adhesive application block applies a first adhesive to a lower surface of the web material between the leading edge of the web material and the web material cuts made by the perforating blade. A connecting adhesive application roller applies a second adhesive to an upper surface of the web material adjacent the web material cuts made by the perforating blade but oil a side of the cuts opposite to the first adhesive. The first adhesive secures the leading edge of web material to the next underlying layer of web material on the roll of web material. The second adhesive contacts and secures the leading edge of new roll web material to a trailing edge of an expiring roll of web material and web material separation occurs along the cuts made by the perforating blade.
In operation, web material is rolled off of the roll to bring the web material into position on the splice preparation apparatus of Norbert et al. The leading edge and perforations are cut and the first and second adhesives are applied to the web material. The web material is then rewound onto the roll and the leading edge of web material is secured to the next underlying layer of web material on the roll of web material via the first adhesive. Unwinding the web material off of the roll to position the web material on the cutting block may result in slack areas or wrinkled areas of web material. These wrinkled and or slack areas of web material may cause the formation of a cut leading edge of undesired or misformed shape (i.e., a waveform leading edge when a straight leading edge is desired). In addition, unwinding and rewinding the web material off and on the roll and a misformed cut leading edge may cause web material wrinkles and web material misalignment due to inadvertent and misaligned adhesion of the first adhesive to the underlying layer of web material.
There is a need for an apparatus and a method for forming a desired accurate cut leading edge for subsequent application of flying splice adhesive tape to the cut leading edge of a roll of web material. Specifically, the application apparatus should substantially eliminate web material slack and wrinkles to permit the accurate formation of a cut leading edge of web material of desired shape, so that the tape can be applied to the cut leading edge of the web material quickly and with alignment accuracy when compared to prior manual and automatic procedures for forming cut leading edges for the subsequent application of flying splice adhesive tape. In addition, the method for eliminating web material slack and wrinkles should not be hand work intensive, cumbersome or tedious.